Yvonne Kelly, an educator at University College London's Institute of Epidemiology and Health Care who co-drove the examination, encouraged guardians and policymakers to take note of its outcomes.
Researchers at University College London studied nearly 11,000 14-year-olds.
Teen girls are twice as likely as boys to show depressive symptoms linked to social media use - mainly due to online harassment and disturbed sleep, as well as poor body image and lower self-esteem, British researchers say.
When the researchers looked at underlying processes that might be linked with social media use and depression, they found 40 per cent of girls and 25 per cent of boys had experience of online harassment or cyberbullying. Only 4% of girls reported not using social media compared to 10% of boys.
"We were quite surprised when we saw the figures and we saw those raw percentages: the fact that the magnitude of association was so much larger for girls than for boys", Kelly said. The data, which came from the UK Millennium Cohort Study, included information from questionnaires on the teens' depressive symptoms and social media use.
Time spent on social media was related to involvement with online harassment which had direct and indirect associations (via sleep, poor body image and self-esteem) with depressive symptom scores. Results revealed that adolescents spending three to five hours of social media per day had a 26 percent increase in depression scores in girls and a 21 percent rise in depression scores in boys. "For girls, greater daily hours of social media use corresponded to a stepwise increase in depressive symptoms", explained Kelly. They noted that girls spent more time on social media than boys and these girls had more pronounced signs of depression than boys.
The team of researchers found that about 40 percent of girls, who spend more than five hours on social media, develop symptoms of depression. Among teenagers who had perpetrated online bullying, 32.8 per cent of girls and 7.9 per cent of boys were depressed.
The study had some limitations, including that the findings show only a correlation between depressive symptoms and social media use, not a causal relationship. They noted than one in two girls and one in four boys had a disrupted sleep "most of the time".
He added that he often points his patients' families to the American Academy of Pediatrics for tips on how to establish healthy social media habits in the home. This was in comparison with teenagers who used it for one to three hours/day.
Social media and internet companies have been criticised for not acknowledging the impact their services have on the lives of young people.